(a) Field of the Invention
The present invention relates to a method and device for transmitting/receiving a media service in a hybrid network. More particularly, the present invention relates to a technique for transmitting/receiving a media service in consideration of switching of a transmission path, a dynamically changing broadcasting network, and a state of a communication network.
(b) Description of the Related Art
Next-generation broadcasting standards such as Advanced Television Systems Committee (ATSC) 3.0 and Digital Video Broadcasting-Terrestrial 2 (DVB-T2) support IP-based multimedia streaming as well as conventional MPEG-2 TS-based multimedia streaming. This explicitly or implicitly aims at configuring a hybrid network that is a combination of a broadcasting network and a communication network and providing a multimedia streaming service, and it is one of important technical objects for the next generation broadcasting system to select a transmission path optimized to a transmission side or a receiving side and switch the transmission network regarding the hybrid network.
Another major characteristic of the next generation broadcasting system allows a plurality of media streams having a variable transmission bit ratio to be dynamically and flexibly allocated to a transmission frame and then be transmitted, differing from the conventional broadcasting system that transmits a fixed number of media streams according to a fixed transmission bit ratio. The above-noted characteristic represented by a concept such as the physical layer pipe (PLP) of the DVB-T2 allows to configure a plurality of logical channels with different modulation methods, different error correction code rates, and different transmission bit ratios in a single broadcasting channel, and dynamically allocate resources among the logical channels so that the broadcasting channel may be flexibly configured to satisfy the transmission bit ratio and the error correction code rate required for transmission, receiving, or services.
To provide the media service with optimal quality on the hybrid network, an optimized transmission path must be selected in consideration of a transmission resource status of the dynamically changing broadcasting network and communication network, and continuity of media data must be maintained when the transmission path is changed or the transmission bit ratio is adjusted. Further, to maintain continuity of media data between the broadcasting network and the communication network, an uncomplicated method for synchronizing media data is needed.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.